/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.format.datetime.joda;

import java.util.Calendar;
import java.util.Date;
import java.util.EnumMap;
import java.util.Map;

import org.joda.time.DateTime;
import org.joda.time.Duration;
import org.joda.time.LocalDate;
import org.joda.time.LocalDateTime;
import org.joda.time.LocalTime;
import org.joda.time.MonthDay;
import org.joda.time.Period;
import org.joda.time.ReadableInstant;
import org.joda.time.YearMonth;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;

import org.springframework.format.FormatterRegistrar;
import org.springframework.format.FormatterRegistry;
import org.springframework.format.Parser;
import org.springframework.format.Printer;
import org.springframework.format.annotation.DateTimeFormat.ISO;

/**
 * Configures Joda-Time's formatting system for use with Spring.
 *
 * <p><b>NOTE:</b> Spring's Joda-Time support requires Joda-Time 2.x, as of Spring 4.0.
 *
 * @author Keith Donald
 * @author Juergen Hoeller
 * @author Phillip Webb
 * @see #setDateStyle
 * @see #setTimeStyle
 * @see #setDateTimeStyle
 * @see #setUseIsoFormat
 * @see FormatterRegistrar#registerFormatters
 * @see org.springframework.format.datetime.DateFormatterRegistrar
 * @see DateTimeFormatterFactoryBean
 * @since 3.1
 */
public class JodaTimeFormatterRegistrar implements FormatterRegistrar {

    /**
     * User defined formatters.
     */
    private final Map<Type, DateTimeFormatter> formatters = new EnumMap<>(Type.class);
    /**
     * Factories used when specific formatters have not been specified.
     */
    private final Map<Type, DateTimeFormatterFactory> factories;

    public JodaTimeFormatterRegistrar() {
        this.factories = new EnumMap<>(Type.class);
        for (Type type : Type.values()) {
            this.factories.put(type, new DateTimeFormatterFactory());
        }
    }

    /**
     * Set whether standard ISO formatting should be applied to all date/time types.
     * Default is "false" (no).
     * <p>If set to "true", the "dateStyle", "timeStyle" and "dateTimeStyle"
     * properties are effectively ignored.
     */
    public void setUseIsoFormat(boolean useIsoFormat) {
        this.factories.get(Type.DATE).setIso(useIsoFormat ? ISO.DATE : ISO.NONE);
        this.factories.get(Type.TIME).setIso(useIsoFormat ? ISO.TIME : ISO.NONE);
        this.factories.get(Type.DATE_TIME).setIso(useIsoFormat ? ISO.DATE_TIME : ISO.NONE);
    }

    /**
     * Set the default format style of Joda {@link LocalDate} objects.
     * Default is {@link DateTimeFormat#shortDate()}.
     */
    public void setDateStyle(String dateStyle) {
        this.factories.get(Type.DATE).setStyle(dateStyle + "-");
    }

    /**
     * Set the default format style of Joda {@link LocalTime} objects.
     * Default is {@link DateTimeFormat#shortTime()}.
     */
    public void setTimeStyle(String timeStyle) {
        this.factories.get(Type.TIME).setStyle("-" + timeStyle);
    }

    /**
     * Set the default format style of Joda {@link LocalDateTime} and {@link DateTime} objects,
     * as well as JDK {@link Date} and {@link Calendar} objects.
     * Default is {@link DateTimeFormat#shortDateTime()}.
     */
    public void setDateTimeStyle(String dateTimeStyle) {
        this.factories.get(Type.DATE_TIME).setStyle(dateTimeStyle);
    }

    /**
     * Set the formatter that will be used for objects representing date values.
     * <p>This formatter will be used for the {@link LocalDate} type. When specified
     * the {@link #setDateStyle(String) dateStyle} and
     * {@link #setUseIsoFormat(boolean) useIsoFormat} properties will be ignored.
     *
     * @param formatter the formatter to use
     * @see #setTimeFormatter
     * @see #setDateTimeFormatter
     * @since 3.2
     */
    public void setDateFormatter(DateTimeFormatter formatter) {
        this.formatters.put(Type.DATE, formatter);
    }

    /**
     * Set the formatter that will be used for objects representing time values.
     * <p>This formatter will be used for the {@link LocalTime} type. When specified
     * the {@link #setTimeStyle(String) timeStyle} and
     * {@link #setUseIsoFormat(boolean) useIsoFormat} properties will be ignored.
     *
     * @param formatter the formatter to use
     * @see #setDateFormatter
     * @see #setDateTimeFormatter
     * @since 3.2
     */
    public void setTimeFormatter(DateTimeFormatter formatter) {
        this.formatters.put(Type.TIME, formatter);
    }

    /**
     * Set the formatter that will be used for objects representing date and time values.
     * <p>This formatter will be used for {@link LocalDateTime}, {@link ReadableInstant},
     * {@link Date} and {@link Calendar} types. When specified
     * the {@link #setDateTimeStyle(String) dateTimeStyle} and
     * {@link #setUseIsoFormat(boolean) useIsoFormat} properties will be ignored.
     *
     * @param formatter the formatter to use
     * @see #setDateFormatter
     * @see #setTimeFormatter
     * @since 3.2
     */
    public void setDateTimeFormatter(DateTimeFormatter formatter) {
        this.formatters.put(Type.DATE_TIME, formatter);
    }

    @Override
    public void registerFormatters(FormatterRegistry registry) {
        JodaTimeConverters.registerConverters(registry);

        DateTimeFormatter dateFormatter = getFormatter(Type.DATE);
        DateTimeFormatter timeFormatter = getFormatter(Type.TIME);
        DateTimeFormatter dateTimeFormatter = getFormatter(Type.DATE_TIME);

        addFormatterForFields(registry,
                new ReadablePartialPrinter(dateFormatter),
                new LocalDateParser(dateFormatter),
                LocalDate.class);

        addFormatterForFields(registry,
                new ReadablePartialPrinter(timeFormatter),
                new LocalTimeParser(timeFormatter),
                LocalTime.class);

        addFormatterForFields(registry,
                new ReadablePartialPrinter(dateTimeFormatter),
                new LocalDateTimeParser(dateTimeFormatter),
                LocalDateTime.class);

        addFormatterForFields(registry,
                new ReadableInstantPrinter(dateTimeFormatter),
                new DateTimeParser(dateTimeFormatter),
                ReadableInstant.class);

        // In order to retain backwards compatibility we only register Date/Calendar
        // types when a user defined formatter is specified (see SPR-10105)
        if (this.formatters.containsKey(Type.DATE_TIME)) {
            addFormatterForFields(registry,
                    new ReadableInstantPrinter(dateTimeFormatter),
                    new DateTimeParser(dateTimeFormatter),
                    Date.class, Calendar.class);
        }

        registry.addFormatterForFieldType(Period.class, new PeriodFormatter());
        registry.addFormatterForFieldType(Duration.class, new DurationFormatter());
        registry.addFormatterForFieldType(YearMonth.class, new YearMonthFormatter());
        registry.addFormatterForFieldType(MonthDay.class, new MonthDayFormatter());

        registry.addFormatterForFieldAnnotation(new JodaDateTimeFormatAnnotationFormatterFactory());
    }

    private DateTimeFormatter getFormatter(Type type) {
        DateTimeFormatter formatter = this.formatters.get(type);
        if (formatter != null) {
            return formatter;
        }
        DateTimeFormatter fallbackFormatter = getFallbackFormatter(type);
        return this.factories.get(type).createDateTimeFormatter(fallbackFormatter);
    }

    private DateTimeFormatter getFallbackFormatter(Type type) {
        switch (type) {
            case DATE:
                return DateTimeFormat.shortDate();
            case TIME:
                return DateTimeFormat.shortTime();
            default:
                return DateTimeFormat.shortDateTime();
        }
    }

    private void addFormatterForFields(FormatterRegistry registry, Printer<?> printer,
                                       Parser<?> parser, Class<?>... fieldTypes) {

        for (Class<?> fieldType : fieldTypes) {
            registry.addFormatterForFieldType(fieldType, printer, parser);
        }
    }

    private enum Type {DATE, TIME, DATE_TIME}

}
